No one has been charged over the death of a young chef and mother of two, following a police investigation into a boat charter that ended in tragedy. 

Danielle Tamarua fell overboard near Rangitoto Island during a staff party on board a Zefiro Charters Ltd vessel in the Waitematā Harbour in April last year. 

Staff of Shallot Hospitality, trading as LittleWolf Catering, were the guests on board the boat. 

Two men had jumped into the harbour in a bid to save the 25-year-old but she was brought back to the vessel unresponsive, a witness told the Herald at the time. 

Investigations were launched by police and Maritime New Zealand. 

Today police told the Herald their investigation has been completed and no criminal charges have been laid. 

"The police investigation has been completed in relation to this matter with no criminal charges laid. The matter has been referred to the Coroner." 

Maritime New Zealand confirmed it has also completed an investigation, but it is unclear if any charges will be laid as a result. 

"The file is now being considered for a decision on next steps," it told the Herald. 

Maritime New Zealand said if non-compliance is identified, it has a range of tools available, including prosecution, prohibiting operations, suspending and revoking a seafarer's licence, imposing conditions and providing advice and suggested safety improvements. 

At the time of Tamarua's death, LittleWolf Catering general manager Marcel Leydesdorff said staff were deeply distressed over the tragedy. 

"Danielle Tamarua was a beautiful, kind and much loved member of our team." 

LittleWolf established a Givealittle page for Tamarua's partner and two young children, and more than $32,000 was raised. 

"Danielle's passing is a huge loss to her young family," Leydesorff wrote on the page. 

"Danielle left us on April 1st, after suffering a tragic accident at our staff party, surrounded by her colleagues and work friends." 

He described Tamarua as "talented young chef" and "much loved member" of the kitchen team. 

The 25-year-old trained as a chef at hospitality education provider NZMA in Grafton and had worked at various restaurants around Auckland.